The Arctic continental shelf seas hold a globally significant source of freshwater that impacts Arctic Ocean
stratification, circulation, and climate. This freshwater can be injected below the surface mixed layer by intense
turbulent kinetic energy dissipation events, as resolved by Laptev Sea microstructure observations. The tides
provide a major source of energy that can be dissipated and hence drive diapycnal mixing in the Laptev Sea.
Multiyear ADCP mooring records from locations across the shelf reveal that semidiurnal tides are dominated
by theM2 and S2 constituents, with the largest amplitudes on the outer shelf. Throughout most of the shelf, tides
are clockwise polarized and sheared by stratification, as characteristic near theM2 critical latitude. Interannual
variations of the tidal and shear structures on the inner shelf aremainly determined by the stratification-setting
Lena River freshwater plume. In all locations,M2 tides are enhanced under sea ice, and therefore changes in the
seasonal ice cover may lead to changes in tides and water column structure. The main conclusions of this study
are that (i) tides play a comparatively greater role year-round on the outer shelf relative to the inner shelf;
(ii) a sea ice reduction will overall decrease the predictability of the currents, especially on the inner shelf; and
(iii) the freshwater distribution directly impacts diapycnal mixing by setting the vertical tidal structure. These
combined effects imply that future sea ice loss will increase the variability and vertical mixing of freshwater,
particularly on the inner shelf, where the Lena River first enters the Laptev Sea.